Exclusion of debris and trash from gutter and storm drains except during high rates of stream flow.
It is the intended function of gutters and storm drains to carry away water during storms that might otherwise flood adjacent areas. It has become commonplace to observe that when unregulated, all of the trash and contaminants from upstream locations will finally arrive at some downstream location to the disadvantage of the environment at the place of ultimate discharge.
A prominent example is Los Angeles County, Calif., where the run-off from an area of many square miles discharges into very local outfalls in the Pacific Ocean at places near to residential and recreational usage. One well-known example is Santa Monica bay, and there are others. Especially after heavy storms, beaches for miles are restricted from public usage until after many tides have diluted and washed away what had arrived at the coast. Similar situations arise elsewhere along many rivers and in many valleys.
The original generation of this burden can be only partially averted by local means. People will still wash cars, rake leaves, and deposit trash in gutters and storm drains. This and other solid debris will somehow reach this major system. However, the storm drainage system is not designed for trash collection. Instead it is intended to protect an urban area from floods of water when heavy rains occur, while still draining away the water generated during normal events, such as light rains and normal processes like over-watering lawns and washing cars.
The problem is that during dry periods, solid materials still find their way into the system, either because of its regular generation upstream, or because people put things into it. Unless removed it clogs the system and will not carry the water away. A flood results. As a consequence, every such system is regularly cleaned out, hopefully before the next heavy rain. Vacuum trucks, persons in hazmat suits going into manholes, and the like regularly do this expensive work.
The least expensive removal work is the mechanical street sweeper. It can routinely sweep up accumulations of solid material, from gutters. However, this cannot be a daily event. Usually it will be once a week. In the meantime, the solids can accumulate or be put into the system.
There can be only partial solutions, anywhere, to the total situation, and they will largely be local. However, each time a problem is at least partially solved upstream, for the load downstream where many upstream sources converge, each one can be an important improvement. The problem is to remove all that one can, while still allowing normal living and natural functions to be accommodated.
It is an object of this invention to exclude during periods of no or low water flow undesirable solid materials from drainage systems. During such dry periods, the solids will remain in their usual first collection sites, mainly gutters. These can be swept away by sweepers, and will not have to be removed from collection basins, nor will they arrive at a river or ocean. The ultimate burden is vastly reduced.
The objective of barring the passage of solids at the entrance of a curb or storm drain opening is shown in Martinez U.S. Pat. No. 6,217,756. This patent shows a pivoted gate at the entrance to a system that remains closed to large solids, but permits flow of water around and/or through it.
An actuator in the form of a bucket is suspended in the system where slowly-flowing water will not reach it, but rapidly flowing water will. When a sufficient weight of water is in the bucket, it will open the gate. Holes in the bucket drain the water, so that sufficient water in the bucket to open the barrier remains only when the flow rate is sufficiently high.
This product depends for its successful operation on the balance between the rate of flow of water into the bucket, and the rate of flow out of its holes. This requires that the bucket and its drain holes remain xe2x80x9ccleanxe2x80x9d. A problem is that debris can accumulate in the bucket and the drain holes can plug up. This is a fail-safe arrangement, because the tendency is to retain water and keep the barrier open. Thus there is no risk of closure which might result in flooding. It can, however, fail to close when the rain stops.
It is an object of this invention to overcome the disadvantages of a system actuated by the collection of water with a dynamic system which, while responsive to rate of water flow, also is self-cleaning, so that in the absence of a sufficient dynamic force, the system remains closed to the entry of solids.
A water flow responsive barrier according to this invention includes a gate pivoted so as to occlude, at least in part, or to leave open, an entry into a drainage system. Its most characteristic application is in the curbside entry into a drainage chamber. Such chambers are enlarged regions intended to hold accumulations of larger solids before they can pass into a larger system downstream from them. Most of these chambers are surmounted by manholes. These manholes are routinely entered to clean them out.
The entry is generally formed at a rectangular opening with two opposite sides, a top, and a bottom sill. Water entering the entry flows over the sill. At slow flow rates water such as overflow from lawns, washing of cars, and light rains, merely drains over the sill, and does not project far into the chamber. As such, it will not actuate the barrier, and the gate will remain closed. Slow water flows past or through it, while the gate continues to bar trash from entering the chamber.
According to this invention, a rotor is pivotally mounted in the chamber where it will be encountered by a rapidly flowing stream, such as from a heavy rain. This rotor carries vanes which are impinged on by the rapid stream which turns the rotor. The rotor then actuates linkage which will pivot the gate open to permit rapid flow of water. It will also pass such solids as may have been permitted to accumulate in the gutter. Flooding will not result.
According to a feature of this invention, the vanes do not accumulate water in the sense of a bucket or container. Instead they act in response to a dynamic load.
Accordingly to a preferred but optional feature of the invention, the vanes are open at least at one end, so there is no risk of their being plugged or accumulating water or debris.
The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which: